Why do you try to make me choose. Can't we all be friends & work together...?!
Given the choice I buy the actual book or an Amazon eBook purely because the mobi files work best on my beloved Kindle. I have an iPad and although it gives me pretty coloured eBooks, it's much heavier to hold & I don't really like reading books on it. BUT as a reviewer sometimes I receive eARCs as iBooks/epub or even PDF files, which either don't load on my kindle or are formatted weirdly. So I have to use my iPad, but this really annoys me. Money making and legalities aside, it really would make readers like me happy to have the option to open the different formats on all devices.